This invention relates to a motion chair, and more particularly to an arrangement for mounting a seat to the legs or frame of a motion chair.
Motion type chairs are shown and described in Leib U.S. Pat. No. 4,784,435 issued Nov. 15, 1988 and U.S. Pat. No. 4,946,224 issued Aug. 7, 1990, as well as in Leib et al U.S. Pat. No. 5,551,758 issued Sep. 3, 1996, all of which are hereby incorporated by reference. The ""435 patent discloses a motion chair having a metal frame that includes a pair of front legs, each of which has a mounting bracket attached to its inside area. A seat is mounted to the brackets, and includes side frame members which form both the seat support and back support areas of the chair. Each side frame member is connected to one of the mounting brackets, such that the seat is cantilevered at the front legs. The side frame members have spring action mechanical properties, to enable the seat support area to deflect downwardly and the back support area to deflect rearwardly and downwardly when an individual sits in the chair. The ""191 patent discloses a similar arrangement, but in which each seat-mounting bracket is connected to a metal support bar, which in turn is anchored to the inside portion of one of the front legs, which are made of wood. This results in a combination wood-metal chair, in which seating loads are borne by the vertical portion of the front leg to which the support bar is attached.
The ""758 patent discloses a motion chair having a metal frame, with a mounting bracket 14 being connected to each vertical upright leg portion of the frame. The seat includes a pair of side members, each of which is mounted to one of the brackets. As in the ""435 patent, the side members have a spring action to impart motion to the seat and back of the chair.
In a metal frame chair, such as is disclosed in the ""435 and ""758 patents, the seat mounting support brackets are connected to the front legs of the chair by welding, wherein the weld connection and the metal front leg are capable of handling the loads and stresses resulting from a user sitting in the chair seat. In a wood frame chair, such as is disclosed in the ""224 patent, the seat mounting brackets are welded to a vertical support bar, which in turn is connected to the vertical wood legs of the frame. The support bar functions to distribute loads and stresses applied to the support bar by the mounting bracket, throughout the length of the connection of the support bar to the vertical front portion of the wood frame. While this construction allows use of a motion-type connection in a wood frame chair, it is somewhat disadvantageous in that it requires a sturdy and strong front leg structure, which can detract from the aesthetic appearance of the chair and which provides limitations in design alternatives for a motion chair of this type.
It is an object of the present invention to provide a seat mounting arrangement for a motion chair, which does not rely solely upon connection of the chair frame mounting bracket to the vertical upright portion of a chair leg for support. It is a further object of the invention to provide such a seat mounting arrangement capable of being used in a chair having a conventional wood frame configuration, in which the size of the frame components is not dictated by the ability to handle loads and stresses applied on a seat mounting bracket, to which the seat is movably secured. It is a further object of the invention to provide such a seat mounting arrangement which can be used in any type of chair frame, to provide a wide variety of design options for a motion-type chair. A still further object of the invention is to provide such a seat mounting arrangement which is relatively simple in its components and construction, yet which provides highly satisfactory operation and a wide variety of design options.
In accordance with the invention, a motion-type chair includes a frame assembly having a pair of side frames, each of which has a front leg and a back leg. Each side frame further includes a side rail support member that extends in a front-rear direction. Each side rail support member is connected at a front end to one of the front legs, and at a rear end to one of the rear legs.
The motion-type chair further includes a seat adapted to support a user, which is typically in the form of a combination seat and back arrangement. The seat has a pair of side seat frame members, each of which is located adjacent one of the support members of the frame. Each seat frame member is preferably formed of a spring steel, as in the prior art, and is connected to a seat mounting bracket for providing resilient, biased movement of the seat relative to the frame assembly.
The present invention contemplates a seat support member that is interconnected with the side rail support member of each side frame. Each seat mounting bracket is connected to one of the seat support members, such as by welding. The seat support member extends in a front-rear direction. The seat support member is arranged so as to be located adjacent, and connected to, one of the side rail support members of the frame. In one form, the seat support member may be an elongated member applied to an edge or other surface of the side rail support member. The seat support member is preferably configured so as to correspond in shape to an edge portion of the side rail support member, so as to blend in with the side rail support member. This enables the seat support member to be incorporated into the chair frame without detracting from the overall appearance of the frame. This construction connects the seat mounting bracket to the frame without relying upon connection to the front leg of the frame to withstand all of the loads and stresses applied by a user sitting on the seat of the chair. In another form, the seat support member may be connected to an inside surface of the side rail support member. The seat support member may be configured to span the joint between the front leg and the side rail support member to avoid stressing the joint, and is preferably located so as not to be visible from the exterior of the frame.
In either form, the loads and stresses applied to the seat mounting bracket are transferred to the seat support member, and in turn are transferred to and absorbed by the side rail support member and the front and rear legs.